Production of valuable hydrocarbons



Feb. 13, 1945. cHANEY 2,369,281

PRODUCTION OF VALUABLE HYDROCARBONS Filed Dec. 28, 1940' 2 Sheets-sheaf 1 SUPERHEATSR CARBURLTOR HYOROC aneofi l nuenb ora/ O ne- ,55%?

Feb;' l3, 194s. 1N. K.CHANEY 2,369,2

I PRODUCTION OF VALUABLE HYDROCARBONS vFiled Dec. 28, 1940 2 Sheets-Sheet 2 laweia fiz wdmd/l Patented Feb. 13, 1945 I This invention pertains generally to t the' production ofwvaluable hydrocarbons from petroleum' oil bylpyrolysisv; a r

The invention involves the production of nonaromatic resin-forming :hydrOcarbgnsrsuch as isobutylene; the dienesnbutadiene,wcyclopentadiene, dicyclopentadiene, isoprene and piperylene; non-alkylated u aromatics hydrocarbons such as benzene naphthalene and anthracene,

alkylaied 1 aromatic hydrocarbons suchtas toluene and xylem; alkenated aromatic hydrocarbons such as styrne, methyl styrenedandx indene; as well as" other aromatic hydrocarbons boiling "above' 200"" C: at atmospherie pressure: and compyrolytically decomposed at high f Normally in the manufacture ot oll gas,pe-

troleum oi' temperatures and frequently under 4 conditions 'ofjreduce'd{partialp-pressures resulting from the presenc-lof"largelyolumes of other gases such as steam or water gas; "the latter being a a mixture mally gaseous hydrocarbons which are f condensible' with difficulty to rn aterials of- 'extremely ai'bonmay also be prolufns or combustibleeas my above mentioned copending is more" particularly addressed low vaporipr'essur'e; such'asfthe less i volatile con- NeivcomlY KQChaney, Moylarl, Pa asslgnor to The United Gas Improvement Company, a cor n 1 n Wel s's a rc iw a .a'ppucaanne ember as, 1940, Serial No. 312,042 a the resin-forming hydrocarbons, f particularly non-aromatic resin-forming hydrocarbons such as the dienes. 1

In my; copending application Serial Number 220,649, filed July 22,, 1938 lwhichnhas matured into Patent 2,226,531, datedpecember 31, 1940, I have described and claimed a cyclic process for making combustible gas w hich as practiced in a gast-makingzset includes the cycle internally preheating said gasimakingfset andla gas-making run involving the ,yapd'r phase cracking of petroleum oil in which the yield of valuable hydmcarbonsyincludin alkylated and alkenated aromatic hydrocarbons isaincreased bylintroducing benzene into saidygas set in addition t 0 said petroleum l du ring the vapor phase 1 cracking of; said petroleum oil.

Other materials and particularly allc ylated benzenes may be introduced ng it the benzene in the above process. h t This application is alcontinuation inpart gf ap ca an n t "i troduccarbqnlat m tion of hydrocarbons :Qfr} 2 1 and l and particularly unsaturated by A ,ocarbons .into

the gas-making set 1 in addition-to said; petroleum .Oil during the-(vapor said petroleum oiLu 1 l In" carrying out zthevinvent p r th petroleum vf'oll is pyrolytically devcomposed in vapor phase insithepresence of onedor moi. of thesabove r substances and v preferably-injthe a presence of a 128K611. as 11 measured 8,121

substantial quantity ofmdiluent gaszywhich is preferably 1 readily: s COIldEl'lSiblG-fi-;S11(i,hj as steam wand which isiflpreferably presents in- 1 sufficient @quantity to [materially :reducv sthenpartiallt pressures of. the hydrocarbons:vapors-:presen erably, the dlluenta:isfwesuppliedaini equivalent to: at leastone par t of she my to three parts of petroleumoili by weight: 3fany; levent -ther volum'ewf' diluent before; condensationwto volume of final gas remaining after condensation down' to approximatelylatmosphericn temperature should loe 'at least: 30%;: mpart on all of th'e' d iluent may comprisumethanewand/or 1 other residual *gas' constituents fo p'art 'of less than '4 carbon :atoms while water 'ga's may he- 'emplo'yedas it is preferred not =to use' water 'gas ainaslarge refer to pyrolyzed ice-:feet-lper gallon of oilpyroly'zed, said cubic eet -being pressur 76p cum. and a temperature Qf GO I".

Generally speaking, the preferred operating conditions are of a cyclic character such as is characterized by the conventional cyclic gasmaking processes, although other types of operations including continuous operation are within the broad concept of the invention.

Also the process is preferably conducted with total pressures at atmospheric or near atmospheric pressure.

Broadly speaking, the process is conducted at average temperatures between 1150 F. and 1800 F. and preferably between 1400 F. and 1650" F.

For convenience the invention will be further illustrated in connection with the drawings which form a part of this specification and in which:

Figure 1 shows an elevation partly in section,

diagrammatically illustrating a cyclic gas-making apparatus; and

Figure 2 shows an elevation partly in section, diagrammatically illustrating a continuous gasmaking apparatus.

Referring to Figure l-this figure illustrates diagrammatically apparatus in which the invention may be performed and comprises a cyclic gas-making set which may be conventional, or otherwise.

I indicates a generator, 2 is a carburetter, 3 is a superheater, and 4 is a wash box. The generator I is provided with a burner generally indicated at 5 with means for supplying fluid fuel such as tar, generally indicated at 6, and with means for supplying air for combustion of the fuel generally indicated at I. Th generator may be provided with secondary airsupply means as at 8. 9 indicates checkerbrick arranged above the combustion space Ill. II, I2, and I3 are steam supply pipes.

The generator I is connected at its upper portion to the upper portion of the carburetter 2 by connection I4. The carburetter is illustrated as devoid of checkerbrick and is provided with oil supply means I5 provided with a nozzle l6 capable of finely atomizing the oil.

The carburetter 2 is connected at its base with the base of the superheater 3 by connection IT.

The superheater 3 is shown provided with the checker brick indicated conventionally at I8. Offtake I9 provided with valve 20 leads from the top of the superheater to the wash box 4, from whence connection 20a provided with valve 2| leads to condensate recovery equipment and a gas relief holder (not shown).

The superheater is further provided with a stack valve 22 and may be provided with a steam supply means such as steam pipe 23. Air supply means such as 24 may be provided for admitting tertiary air to the superheater.

The generator I may be provided with the gas oiitake 25 provided with valve 23 and leading from the lower portion of the generator I to the wash box 4.

The carburetter may be provided with checkerbrick as well as the superheater.

Other fluid fuel than tar may be employed for heating the generator I, such for instance, as oil or gas. Further, the generator may be provided with a grate and solid fuel burned thereon for heating instead of fluid fuel, if desired.

Thermocouples such as th shielded thermocouples 29, 30, 3|, 32 and 33 may be provided at spaced intervals through the vaporizing and cracking chambers, their connections leading to temperature recorders (not shown) An illustrative cycle of operation of the apparatus of Figure 1 will be given.

In operation of the apparatus of Figure 1, fluid fuel such as tar, oil or gas is admitted to the generator burner 5 and burned in the generator, with air supplied through pipe I. Secondary air may be supplied through air supply pipe 8. The burning products pass from th generator to the carburetter 2 by way of connection I4 and thence through the carburetter to the superheater by way of connection il. Tertiary air may-be supplied through air supply means 24, if desired. The combustion products pass through the superheater and through the stack valve 22 to atmosphere or to a waste heat boiler (not shown). During this operation, the stack valve 22 is open and valves 20 and 26 are closed.

This operation, termed the blow, heats and stores heat in the checkerbrick and lining of the generator, the lining of the carburetter and the checkerbrick and lining of the superheater.

The tar may then beshut off and a short air purge made by air admitted through air supply means I, followed by a short steam purge with steam supplied to the base of the generator as at I3. The purged products pass out of the set through the stack valve 22.

After the set is purged, and with the stack valve 22 closed, valv 26 closed, and valves 20 and 2| open, petroleum oil is admitted to the carburetter top and finely atomized by the nozzle I3. Simultaneously, C2 hydrocarbon material and/or 03 hydrocarbon material is admitted to the carburetter through the nozzle 36. At the same time, steam is admitted to the generator through the steam supply in the generator base, heated in passage through the generator checkerbrick and passed into the carburetter top by way of connection I4. A portion or all of the steam may be admitted through the steam supply means I2 at the generator top above the checkerbrick instead of 40 through I3 at the bottom and/or the temperature [ill of the steam may be controlled by proportioning the quantities admitted to the two portions of the generator, orotherwise.

The oil is vaporized in the carburetter in the presence of the hydrocarbon additive and the superheated steam from the generator, the quantity of steam being sufflcient to materially reduce the partial pressures of the hydrocarbon vapors.

The vaporized oil and hydrocarbon additive and the steam pass down through the carburetter and into the superheater through connection I1. Some pyrolysis and synthesis may take place in the carburetter.

From the base of the superheater the vaporized oil, hydrocarbon additive, steam, partially cracked vapors and partially synthesized vapors pass upward through the superheater checkerbrick in which. the desired pyrolysis and synthesis are completed.

The reaction products and steam pass through connection I9, the wash box 4, and connection 20a to a relief holder (not shown) and through condensing or other apparatus (not shown) 'for the removal of the desired products from the gas.

2,369,981 v 3 with steam, orsteam and oil, or steam and oil then be further treated "forthe-removal'ot lower and hydrocarbon additive supplied through supboiling hydrocarbonsthereirom. I i it ply means 23, or otherwise. In sucn case; the The wash bos [in which the' 'gasf comes into stack valve 22 is closed, valve 20 is closed and contact with water and 'the water cooledconvalve 26 open. The steam. or steam and oilva- 5 densers cool the gas down t'oan approp ate or pors, or steam and oil and hydrocarbon additive desired temperature which is usually atmospheric vapors and reaction products pass. reversely or somewhatabove. Asaresult'the tar separates through the superheater, carburetterand generas condensate from the gasMThis tar may be ator and through connection 25 to the wash box considered roug y as being mbo'sed or three and to the relief holder (not shown). portions," namely, light oil which may be consid- The fluid fuel burner as a means of providing ered as that portion boiling up to say ap x heat during the blow is preferred, but "recourse y 0 dead y cons dmight be made to the use of a solid fuel bed as e as that po t n ng etween say-approxin the conventional water gas generator, with the m C- d D C- Or he andresiddifference that it is preferred not to pass any 15 ualttarr i it i i 7 large quantity or water gas through the carbu- Thelight oil-traction contains-substantiallyail retter and superheater during the oil cracking 1 e'l den .dl y pentadiene,methyl' styrene, period. Other means for superheating steam the a pfl 0 t e ty ene. yleneand tolufor the process might be then employed, or, sat- B e part Of t e benzene and other misurated steam employed. The use of superheated :0 cellaneous hydrocarbons such as benzol forerunsteam, however. is preferred as it reduces the heindlvidual hyd b mflybe'rm heating load on the carburetter. re from i -oi y a y suitable means, for During the blow, the operation is conducted P QIF t l t n-Q" u to obtain the desired distribution of heat through- Usual as p acti e d s not ca r e condenout the carburetter and superheater. Sation fi y l The following table will illustrate a typical o over from the as ower boi inehydroswing in temperature at various points in a given carbons such as therestj f the styrenegxyle'ne, set during a typical blow. The temperatures tolueneand benzene. cyclqpentadiene.b pif were determined by the standard shielded type p but dlene and blltyleneslspecial measof thermocouple, ures are employed;toeifect condensation ofwhieh Table 1 it refrigeration, compression;absorption and a'dsiiirption or 'any combinationthereof- 'arejexam "*W Y r-wr. v i "I l I .1'91. l 7

- H le mprrulurt 'lgvm wrature l e lndividha] pa t Point In at I. start of F. illld l) 5 from the a a od w 'quently involve" fractionaldistillatidiii" Carburetter top H gggtszgigrggr sum w merbal trv s i to e pi j lv- Superheater middle. n j =rolyzing v nfl e. I ha p Superheatertop pylene; and" propane; or"co inbinations"of these Mg-setmnwmw't mat'rialsfwlth or withoufi other"gaseous sub- -stainces such" as methane and hydrogen normally I U n occurring tni-esiouerges'esw ns smal henwill vary with operating conditions and'thenatura, j'g QB- Q Q hyd fq b n and h ghlff and size 0! the set and the set liningsna eck-i" is? "The t j" 'i e l i a a ei mpl yed erbrick or other heat storage material. is tube construedasthatflportic-n offthefgas from which-substantially u o'ffth hyd' j vep d t M The temperature gradient turally se v the blow may be modified prio "to them Q injection of steam of other fluids tot the carburetter and/or th b' e' of the superheater and/or and/or otherwise. It may" v ger pa'r'flof 'As an "exam ple, a sample of residual gas suitable for employ- ""inllll in Ifthis"process showed" upon"a can .8 A 014%, l

move peak temperatures as d m in copending application Se at filed February 19, 1938, byfE win The point or points ofint or hydrocarbon additive ma diiferent gas making equi chosen for illustration. l,

The oil whether coming nt v I fractory surfaces in signifi ntdu t subjected to the temperatures and superheater and is deep ence of the hydrocarbon additive;

The temperatures given above in character. f

The above is a description ofa. cycle chosen for illustration egrcept carbon additive is introduced nt lyzing environment. Any other cle might be substituted. 1

After passing through th is passed through a relief h water cooled condensers or be considerably varied with variations in the cycle ,and method of operation, it may not be desirable to introduce the additive at the pointof admission of petroleum oil, as the zone of maximum free radical production will necessarily vary with the variation in temperature distribution.

The oil gas apparatus and cycle earlier described were given merely for convenience in illustrating the apparatus and process adapted for use with my invention and are subject to very wide modifications.

Referring now to Figure 2 wherein cracking apparatus of the continuous or continual type is illustrated on a laboratory scale, 45 comprises a reaction tube which may be any suitable material such as quartz, or any of the materials employed in continuous or continual cracking operations.

Tube 45 at its inlet end is shown provided with a. batile 41 in the form of a cup into which project hydrocarbon feeding tube 48 and steam feeding tube 49. Feeding tubes 48 and 49 pass through and form a gas-tight fit with a closure member 50 for the inlet end of tube 45.

Tube 45 adjacent its outlet end is provided with a gas delivery side arm 52 and a closure member 53, the latter being sufliciently below side arm 52 to form a well 54.

Tube 45 is also shown provided with an axially arranged tube 55 of small diameter. Tube 55, as shown, projects through closure members 59 and 53 and provides a convenient way of arranging thermocouple junctions for the measure of temperature. Tube 55 may be of any convenient material, such as quartz, or any other material suitable for continuous or continual cracking purposes.

Tube 45 may be of any convenient length which is usually correlated with the provisions for feeding steam and additive and for feeding and vaporizing oil in order to make it possible to obtain times of contact within a desired range.

For temperature control purposes, tube 45 is shown surrounded with a heating member 51 in the form of a resistance winding which may be provided with several taps, as illustrated at 58; a cooling coil 59 of tubular construction for the flow of cooling fluid; and another resistance winding 59 provided with suitable taps, illustrated at 5|. a

It will be seen that the provision of a cooling coil 59 between resistance windings 51 and 99, and the provision of taps 58 and 5| on windings 51 and 59 respectively, make it possible to closely control temperature conditions within tube 45 as well as to vary such conditions along tube 45. if and as desired.

Assuming that heaters 51 and 59 and cooler 59, if necessary, are operating to establish desired temperature conditions within tube 45, the operation of the apparatus shown in Figure 2 is as follows:

Oil is fed through tube 48 and steam and gaseous hydrocarbon additive are fed through tube 49. These materials strike baflle 41 thus becoming mixed. The resulting reduction in partial pressures of hydrocarbon vapors and the surrounding temperatures are ordinarily suflicient to vaporize all of the hydrocarbons present.

The vaporized hydrocarbons in passing through tube 45 in the presence of steam or other diluent are pyrolyzed and synthesized in a manner similar to that already described in connection with Figure 1.

buretter and superheater above described may Because of the temperatures involved substantially all of the materials except some fre carbon remainin the vapor phase and pass ofi through delivery arm 52 with the as. The tar and lower boiling condensates may be separated from the gas in any desired manner, for example, as already described in connection with Figure 1.

Th following table will illustrate typical temperatures at various points in tube 45 duringthe practice of my invention. The temperatures at the various points were determined by inserting thermocouples in tube -It may be desirable to have the section of the tube below cooling coil 59 relatively short or to operate it at a temperature above 1150" F. to obtain extended times of contact, in which case cooling coil 59 would usually be inoperative.

Thus as particularly described, the portion of the tube '45 above the cooling coil 59 constitutes the chief pyrolyzing chamber, and the portion of the tube below the cooling coil 59 is maintained at a temperature sumciently high to avoid condensation of heavy tars whether or not such temperature is sufliciently high to substantially prolong the pyrolysis. I

The apparatus in Fi r 2 is of course largely for illustration and may be replaced by a plant size unit or units.

If desired, tube 45 may contain refractory material of suitabl size and shape, particularly if suilicient free space is afforded for the flow of vapors, such additional refractory materials providing additional contact surfaces.

Any other heating means may be added or subfrom which they may be removed during cleaning by removal of closure member 53.

when the walls of tube 45 become coated with a layer of carbon sufliciently thick to interfere with proper heat exchange, or otherwise, it may be removed by any suitable means, such as by passing air or oxygen in through tube 48 or 49, or both, the products of combustion being removed through side arm 52.

As an example of increased yields of valuable hydrocarbons in the laboratory apparatus of Figure 2, the following may be given.

A crude oil and approximately 38% by weight of residual gas substantially free from hydrocarbons of more than two carbon atoms were pyrolyzed in the presence of each other under closely similar conditions of temperature and time of contact as a control employing 100% of the same 4 terior pyrolyzed and synthesized. The table below shows the increased yields of certain valuable hydrocarbons especially benzene.

. Pounds of oil topounds of steam:

Tab v With Without residual residual gas gas Pounds of oiltopounds of steamur 1.07 to 1 1.21 to 1 Avg. temperature above baflle 47... F.. 528 835 Time of contact above baiiie 47l.scconds.. .290 .289 Avg. temperature 1,540 1,512 w l. cooling (201169 .'...1. .932 .697 Avg. temperature of cooling tlon 1,040 1,093 Time of contact- 751 756 1.396 1.129 .735 .569 N apthalene #lgal oil pyrolyzed .037 .015 Styrene #Igal. oil pyrolyzed .083 .078. Residual gas (gross) #lgai. oil pyrolyze 5. 622 3.198

As an example of {increased yields of valuable hydrocarbons in the same apparatus employing as additive residual gas not stripped of C3 hydrocarbons but substantially free from hydrocarbons orfourcarbonfatoms, the following may be given.

Acrude oil and 42'% eras weight or said residual gas were py other under closely similar conditions or temperature and time ofcontact as the control of Table 3.

rolyzed in the presence of each Ineach case steam-was admitted with the ma terial pyrolyze V creased yields of cer especially buta e'newith it residual Pounds of oil to pounds of steam, Avg.tempereture abovebaflle 4 F-; Time or contact abovezbaiiie 47;.seconds Avg. temperature een beilie 47 and cooling c0050. Time of contact betwe cooling coil 59 r r seconds Avg. temperature eoo1ingcoilsect1on. F;L 1 Time. olq contact; cooling .j coil gsection N H seconds A vg. temperature below cooling coil. 3F.

,w r ir- Residual gas il /gal.

As another: exampleaa. mixture of :the ofs-Tableeu l andu8.3% of u itswweight of ethylene (alone) Erwere pyrolyzedwtogether under similar conditionsiofetemperature and time ofgcontactcas a. controliemployed -said crude oi1alone. The- 1701:

lowing tableshows theresults. Table T Avg. temperature above battle 4 Time of Avg.

Time ofg eontact be e cooling c0059.. Avg. temperature Time oimonta t Avgl temper iii T me. mw ta t lienzenetlgaLoilp y Tolueneflgal loi yrol l le h h ens #15 ol oy l :Without, Ethylene H The table below shows the in tainyaluable hydrocarbons;

7 comprising conductingwsaid pyrolysis ot petro material from As an exampleoi' the use of propylene alone as additive with apparatus of the character-shown in Figure 2, the following may be given;

The crude oil oi'lable 5 and 11.4% of its weight of propylene (alone) were pyrolyzed together under similar conditions of temperature and time of contact as the control of Table 5. The results are given in the following table.

. Table 6 with Without propylene. propylene Pounds of oil to pounds of steam 1.07 to 1 1.09 to. 1 1 Avg. temperature above baflle47 F. 746 616 Time ofcontect above baflle 47. see0uds .325 .249. Avg. temperature between baflle 47 and cooling 001151;... .F.. 1,545 1,539 Time of contact between baflle 47 and cooling coil 59 ..s econds.. .772 .859 Avg. temperature cooling coil sectlon-F 1 082 1, 044 Time of contact "cooling 0011. section i i seconds" .251 .262, Avg. temperature below cooling eo1l. F.. 735 740 Time of contact below cooling coil 1 a i v M sec0nds 1.183 1.197. Benzene #lgal. oil pyroiyzed 760 648 'loluene ii /gel. oil pyrolyzed .214 180 Solvent naphtha #lgal. oil pyrolyzed. .245 178 Dead oil #/ge.l. oil pyrolyzed.. 1645 .403 Butadiene #lgal. oil pyrolyzed;;. .142 .100 Cyciopcntadiene. (and dimer) #/g ell pyrolyzedflrn L J .081 .047 Isoprene and piperylene #lgal. oil 1 pyit i t roiyzed", .097 .053 Methyl styrenet lgalroll pyrolyzed i .060 l .042 Residual gas (gross) #3131, oil pyrolyzed... 3; 501 3, 102

The foregoing examples clearly demonstrate the advantages of myprocessin the production of vaiuablehydrocarbons. -11

that 'many forms of apparatus may be substituted thereforu In the claims term f petroleurn oill 111-: I

tendedto havetzthermcaningzcommonly accepted 3 in the art,-namely crude-oilandiphysically sepa-v rated fractions thereof; t

It willwalso ibefl understood sions, additions; substitutions and/ or modifications may bemade xwithinithelscopeof the claims without departing from the: spirit of. :the inven- 1. In a -process for making 1 valuable unsatu rated resin-forming "hydrocarbon material which involves the vapor phase-pyrolysis -of: petroleum oil, tthe steps or increasingjthe recovery of saturated resin-forming .iw hydrocarbon material leumi oil under pressureuconuitions =not" widely departing. from atmospheric pressure and in the presence of addednormallyrigaseous hydrocarbon material. selected them a the: roup consisting 0f" products of petroleum oil =pyrolysis and (2) a propylene fractionflofthe"normally gaseous prod ucts 'of petroleum 01 1"pyrolysis"and separating' said unsaturateds resin iorming hydrocarbon;

rthe products bf aid vapo *pnese pyrolysis."

2; 1n a process or m'a 0 rated resin forming hydrocarbon mtena which I s If that changes.

consisting of (1) an ethylene fraction of the normally gaseous products of petroleum oil pyrolysis and (2) a propylene traction of the normally gaseous products of petroleum oil pyrolysis, and

separating said unsaturated resin-forming hydrocarbon material from the products of said vapor phase pyrolysis.

3. In a process for making valuable unsaturated resln-forming hydrocarbon material including unsaturated resin-forming aromatic hydrocarbon material which involves the vapor phase pyrolysis of petroleum oil, the steps of increasing the recovery of said unsaturated resin- I eluding conjugated dioleflne material which in-.

volves the vapor phase pyrolysis oi! petroleum oil, the steps of increasing the recovery of said conjugated dioleflne material comprising conducting said pyrolysis of petroleum oil in the presence of an added quantity of a propylene fraction separated from the normally gaseous products of petroleum oil pyrolysis remaining after removal of butadiene, and separating conjugated diolefine material from the products of said vapor phase pyrolysis.

5. In a cyclic process for the production of valuable resin-forming unsaturated hydrocarbon material including resin-forming unsaturated aromatic hydrocarbon material involving the storing of heat in heat storage material by the combustion of heating gases during a heating portion of the cycle and the employment during a petroleum oil pyrolyzing portion of the cycle of said stored heat for the vapor phase pyrolysis of petroleum oil, the steps of favoring an increased recovery of said resin-forming unsaturated aromatic hydrocarbon material which comprise conducting said vapor'phase pyrolysis by said stored heat under temperature conditions between 1150 F. and 1800" F. in the presence of an added quantity. of an ethylene fraction separated from the i normally gaseous products of petroleum oil pyrolysis, and separating resin-forming unsaturated aromatic hydrocarbon material from the products or said vapor phase pyrolysis.

6. In a cyclic process for the production of valuable resin-forming unsaturated hydrocarbon material including conjugated dioleflne material involving the storing of heat in heat storage ma-, terial by the combustion of heating gases during a heating portion of the cycle and the utilization during a petroleum oil pyrolyzing portion of the cycle 01 said stored heat for the vapor phase pyrolysis of petroleum oil, the steps of favoring an increased recovery of said com'ugated dioleflne material which comprise conducting said vapor phase pyrolysis by said stored heat in the presence of an added quantity of a propylene fraction separated from the normally gaseous products of petroleum oil pyrolysis remaining after removal of butadiene, and separating conjugated dioleflne material from the products of said vapor phase pyrolysis.

7. In a cyclic process for the manufacture of valuable resin-forming unsaturated hydrocarbon material including butadiene involving the storage of heat in heat storage material by the combustion of heating gases during a heating period of the cycle and the utilization of said stored heat during a petroleum oil pyrolyzing period of said cycle for the vapor phase pyrolysis of petroleum oil, the steps of favoring an increased recovery of butadiene which comprise conducting said vapor phase pyrolysis of petroleum oil by said stored heat under temperature conditions between 1150' F. and 1800 F. in the presence of an added quantity of a propylene traction separated from normally gaseous products of the petroleum oil pyrolysis remaining after the removal of butadiene, and separating butadiene from the products of said vapor phase pyrolysis.

8. In a cyclic process for the production of valuable resin-forming unsaturated hydrocarbon material including conjugated dioleflne material 01' more than three and less than six carbon atoms per molecule involving the storage of heat in heat storage material by the combustion of heating gases during a heating portion of the cycle and the utilization of the stored heat in a petroleum oil pyrolyzing portion of the cycle for the vapor phase pyrolysis oi petroleum oil, the steps of favoring an increased recovery of said conjugated diolefine material which comprise conducting said vapor phase pyrolysis by said stored heat in the presence 0! diluent steam and of an added quantity of a propylene traction separated from the normally gaseous products of petroleum oil pyrolysis remaining after removal of butadiene, conducting said pyrolysis under temperature conditions between 1400 F. and 1800 F., and separating said conjugated dioleflne material of more than three and less than six carbon atoms per molecule from the products of said vapor phase pyrolysis.

9. In a cyclic process for the production of valuable resin-forming unsaturated hydrocarbon material including conjugated dioleflne material of more than three and less than six carbon atoms per molecule involving the storage of heat in heat storage material by the combustion of heating gases during a heating portion of the cycle and the utilization of said stored heat during a petroleum oil pyrolyzing portion of the cycle for the vapor phase pyrolysis of petroleum oil, the steps of recycling into the petroleum oil pyrolyzing environment during the petroleum oil pyrolyzing portion of the cycle a propylene fraction separated from the normally gaseous products of said vapor phase pyrolysis after the removal of butadiene therefrom, conducting said vapor phase petroleum oil pyrolysis under temperature conditions between 1150' F. and 1800' F. in the presence of steam and said recycled propylene fraction, and recovering said conjugated dioleflne material from the products of I said vapor phase pyrolysis.

10. In a cyclic process for the production of valuable resin-forming unsaturated hydrocarbon material including conjugated dioleflne material of more than three and less than six carbon atoms per molecule involving the storing of heat in heat storage material by the combustion of heating gases during a heating portion of the cycle and the utilization of the stored heat during a petroleum oil pyrolyzing portion oi the cycle for the vapor phase pyrolysis oi. petroleum oil, the steps of favoring increased recoveries of said conjugated dioleflne material which comprise conducting said vapor phase pyrolysis by said stored heat under temperature conditions between 1400" F. and 1800 F. and in the presence of a quantity of added diluent gas at least equivalent to 30% of the volume oi. gas resulting from said pyrolysis when said resulting gas is measured at atmospheric temperature and pressure, said added diluent gas comprising steam and added normally gaseous hydrocarbon material, separately recovering said conjugated dioleflne material from the products of said vapor phase pyrolysis, separately recovering a residual gas from said products substantially free from hydrocarbons of more than four carbon atoms per molecule and relatively free from conjugated diolefine material, separating a propylene fraction from said residual gas and employing said propylene fraction as a portion of said added diluent gas in said vapor phase pyrolysis.

11. In a cyclic process for the production of valuable resin-forming unsaturated hydrocarbon material including conjugated dioleflne material of more than three and less than six carbon atoms per molecule involving the storing of heat in heat storage material by the combustion of heating gases during a heating portion of the cycle and the utilization of the stored heat during a petroleum oil pyrolizing portion of the cycle for the vapor phase pyrolysis of petroleum oil, the steps of favoring increased recoveries of said conjugated dioleflne material which comprise conducting said vapor phase pyrolysis by said stored heat under temperature conditions between 1400 F. and 1650 F. and in the presence of a quantity of added diluent gas at least equivalent to 30% of the volume of gas resulting from said pyrolysis when said resulting gas is measured at atmospheric temperature and pressure, said added diluent gas comprising steam and added normally gaseous hydrocarbon material,

pyrolysis, separately recovering a residual gas from said products substantially free from hydrocarbons of more than four carbon atoms per molecule and relatively free from conjugated diolefine material, separating a propylene fraction from said residual gas and employing said propylene fraction as a portion of said added diluent gas in said vapor phase pyrolysis.

12. In a cyclic process for the production of valuable resin-forming unsaturated hydrocarbon material including resin-forming unsaturated aromatic hydrocarbon material involving the storing of heat in heat storage material by the combustion of heating gases during a heating period of the cycle and the utilization of the stored heat during a petroleum oil pyrolyzing portion of the cycle for the vapor phase pyrolysis of petroleum oil, the steps comprising conducting said pyrolysis under temperature conditions between 1400 F. and 1800 F. and in the presence of an added ethylene fraction separated from the normally gaseous products of pyrolysis of petroleum oil after the separation therefrom of substantially all hydrocarbon material of more than four carbon atoms per molecule and after the removal therefrom of butadiene, and separating said unsaturated resinforming hydrocarbon material from the products of said vapor phase pyrolysis.

NEWCOMB K. CHANEY. 

